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TBS Infrastructure · Email security

SPF, DKIM and DMARCmonitoring with clear fixes

Stop others sending fake emails in your company's name — and know when someone changes your DNS. TBS Infrastructure checks your domain's email protection every day, alerts you when name servers or mail servers change, and checks your servers on spam blacklists.

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TBS Infrastructure monitoring screen with outside checks: uptime, certificates, DNS & email, blacklists & ports (sample data) — Real TBS Infrastructure screen · sample data

WHY IT MATTERS

Your domain is your identity

SPF, DKIM and DMARC are three DNS records that tell other mail servers which emails really come from your company. When they are missing or weak, criminals can send invoices and payment requests that look like they came from you — and your real emails are more likely to land in spam.

These records also change over time: a new email service is added, a DNS provider is moved, a record is edited by mistake. TBS Infrastructure checks them every day, grades them, and tells you in plain words what to fix first.

📧

SPF check

Is there exactly one SPF record, does it end safely, and does it stay within the lookup limit?

✉️

DMARC check

Is DMARC set, is it only monitoring (p=none) or really protecting (quarantine / reject), and are reports sent?

🔑

DKIM keys

Checks the DKIM keys for the selectors your mail service uses (up to five per domain).

🧭

DNS change alerts

An alert when name servers (NS) or mail servers (MX) change — a common sign of a mistake or a takeover.

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Blacklist checks

Daily check of your servers' public addresses on free spam blocklists, with what to do if one is listed.

🛡️

Open-port check

Once a day: ports attackers love — databases, Remote Desktop, file sharing — tried from the internet on your own servers.

Honest limits: TBS Infrastructure checks and explains your records — it does not change your DNS for you. Blacklist checks use free public lists.

GOOD TO KNOW

Built to avoid false alarms

DNS down is not "records removed"If a DNS server does not answer, TBS Infrastructure keeps the last result and shows a note — no false alarm.

Only real changes alertThe first check is your starting point; after that, one alert per real change.

Plain-language fixesEach finding comes with the next step to take, not just a red mark.

Free check, no loginThe free domain health check runs the same email checks once, in seconds.

All in the monthly reportEmail-security grades are part of the one-page monthly PDF.

ExportsDNS results, blacklist and port findings as Excel / CSV or through the read-only API.

FAQ

Questions

What are SPF, DKIM and DMARC?

Three DNS records that tell other mail servers which emails really come from your domain. Together they make it much harder to send fake emails in your name.

How often is my domain checked?

Once a day, and you can run a check now when you have changed something.

Does TBS Infrastructure change my DNS records?

No. It checks and explains them; you or your DNS provider make the change.

Which DKIM selectors are checked?

The ones you add for your mail service — up to five per domain. The free check tries common selectors such as selector1, selector2 and google.

Can I test my domain for free?

Yes. The free domain health check runs SPF, DKIM, DMARC and blacklist checks with no login.

Protect your domain's good name

Try the live demo now — real screens with a sample company, nothing to install — or see it on your own servers in a short call.